1. Field of the Invention
The field of the invention is evaporative coolers and improvements to evaporative coolers.
2. Description of the Related Art
In areas of the United States Southwest which are hot and dry, the evaporative cooler is popular and works very well to cool the temperature of air for use in home and business space cooling. Evaporative coolers function by drawing air across water soaked pads and in the process, drop the temperature of the resulting air/water vapor mixture 10 to 15 degrees. They have been developed to a very high degree in the Southwest since they are much less expensive to purchase and to operate when compared with conventional space air conditioners.
In general, an evaporative cooler consists of a substantially cube shaped structure usually about 3 feet to 4 feet on each side with a squirrel cage type blower and motor interiorly to the structure. Each of the three or four sides (depending upon whether the evaporative cooler is a side-draft or down-draft model) have louver type openings through which pass outside air. Immediately adjacent to the louver openings, and inside the evaporative cooler, are pads, generally made from wood which has been processed to resemble straw. In many cases the pads material is called excelsior. These wood fibers are bundled into planar type pads of an inch or so in thickness and placed into the cooler against the single panel sides next to the louvered openings. At the top of each of the panels which make up the sides of the coolers is situated a water trough which receives water from a multi-legged spider, the spider having a plurality of pipes or tubes converging to a centrally located distributing manifold in the top of the cooler. Openings in the troughs allow water to drip onto the pads to percolate therethrough. Air drawn through the pads evaporate the water and in doing so, cools the resultant air/water vapor mixture. The bottom of the evaporative cooler is used as a sump to gather the water percolating through the pads which is not evaporated. A recirculation pump returns the water from the bottom of the cooler to the distributing manifold of the spider.
In the interior of the evaporative cooler is the means by which air is pulled into the evaporative cooler through each of the louvered sides and the means to forcibly eject the air out of the evaporative cooler. This usually comprises a squirrel cage type blower situated interiorly to a blower housing, the housing having openings proximate each end of the squirrel cage blower axle bearings for air intake into the housing. Air taken into the blower housing is outputted through a conduit or duct connecting with the housing. A motor which rests on the outside of the blower housing has a pulley which connects with a belt to another pulley attached to the squirrel cage blower axle.
Evaporative coolers divide into two main groups, a down-draft type and a side-draft type. In the down-draft evaporative cooler, the conduit or duct directing air out of the cooler from the blower housing is downward (when the cooler is setting upright) and blows the air downward out of the cooler. In the down-draft type cooler, all four vertical sides of the cooler cube have louvered openings and have pads receiving water proximate the louvers. In the side-draft evaporative coolers, the conduit or duct from the blower cage housing exits one of the four vertical sides of the cooler (when the cooler is upright). In this type of cooler, only three sides of the four vertical sides have louvered openings and water receiving pads behind them.
Obviously, the down-draft type evaporative cooler for a same size cube construction provides more area exposed to the surrounding environment through which air may pass in its movement to the interior of the cooler to be blown out through the exit conduit or duct. This provides for increased efficiency of the cooler in that, by allowing more air to pass and thus to evaporate more water, a greater volume of the resultant air/water vapor mixture is achieved. On the surface then, it is readily apparent that, absent other factors, the down-draft evaporative cooler may be up to 1/3 more efficient than the 3 sided side-draft evaporative cooler. Increased efficiency will also show up in power consumption by the electrical motor since the motor and blower will have more air available to it through the increased louver openings and not have to work as hard for the air as in the side-draft model. Nevertheless, considerations external to the evaporative cooler usually determines which cooler will be used, primarly the home construction.
Thus it is readily apparent that for the same general sized cube evaporative cooler, increased louver and pad area available for allowing passage of outside air into the interior of the evaporative cooler results in a more efficient and better operating evaporative cooler, one that draws less electrical power to the electrical motor and which effectively cools a larger volume of air per unit time.
Thus it is readily apparent that if the louver opening and pad area of a standard evaporative cooler shall be increased, a resultant efficiency in evaporative cooler results.
It is therefore also obvious that for designs for evaporative coolers including increased louver openings and pad area, the efficiency of the evaporative cooler is enhanced.